This Shared-Instrumentation Grant (SIG) supports an ultrasonic tissue analysis system for use by investigators at Riverside Research Institute (RRI) and collaborating researchers at the Cornell University Medical College (CUMC), Dr. Coleman, PI, NIH Grant EY-03183; the Columbia University College of Physicians and Surgeons (CUCPS), Dr. King, Co-PI, NIH Grant CA-38400; the Memorial Sloan-Kettering Cancer Center (MSKCC), Dr. Fair, Co-PI, NIH Grant CA-53561; the Medical College of Pennsylvania (MCP), Dr. Sigel, PI, NIH Grant HL-41874; and the New York University Medical Center (NYUMC), Dr. Shupack. The RRI investigators are Dr. Lizzi (NIH Grants EY-01212 and CA-38400) and Dr. Feleppa (NIH Grants CA-53561 and HL-41874). The computer-based SIG system. is a complete laboratory facility for acquiring and analyzing ultrasonic data, and displaying computed results in an interactive fashion. The system provides for advanced analysis of radio-frequency (rf) echo signals to characterize tissue microstructure. It includes two- and three-dimensional scanning and analysis, surface-roughness measurements, and very-high-resolution examinations. It will be used to test new concepts and theoretical results, to measure tissue properties, characterize new transducers, and to conduct new pilot studies. The system will expedite and enhance on-going NIH-sponsored research to evaluate the eye, abdominal organs, vasculature, and the prostate gland. It will also be used to examine new applications involving organs such as the skin, breast, and heart.